Modern bicycles have pneumatic tires that provide good traction and reduce the transmission of vibrations caused by a rough surface. An inner-tube is commonly used to contain pressurized air within the tire. A valve assembly is coupled to the inner-tube to provide a mechanism for inflating the inner-tube. The valve assembly is commonly positioned through a hole in a bicycle rim so that the free end of the valve assembly is available to receive a pump head for inflating the tire.
One common type of bicycle valve is called a Schrader valve, as illustrated in FIG. 1. A Schrader valve typically includes a rubber-coated housing 10 and a threaded tip 12. A moveable valve core 14 is positioned completely within the valve housing. A valve cap (not shown) can be threaded onto the valve tip 12 to inhibit entry of dirt and moisture into the valve housing 10.
FIG. 2 illustrates another type of bicycle valve called a Presta valve. The Presta valve includes a valve housing 20 having a threaded exterior body 22 and a threaded tip 24 having threads of a different diameter and a different pitch. A moveable valve core 26 is positioned within the housing, and includes a valve stem 28 extending from the threaded tip 24, and a knurled locknut 30 that is used to lock the valve in the closed position. A threaded nut (not shown) can be threaded onto the body 22 to secure the housing 20 relative to the rim 32. A valve cap (not shown) can be threaded onto the valve tip 24 to inhibit entry of dirt and moisture into the valve housing 20.
As noted above, the presence of threads on the exterior of the valve housing on the above-described bicycle valves facilitates the attachment of valve caps and locking nuts. These external threads are commonly engaged by a pump head during the process of inflating the tire. The interaction between the pump head and the external threads has been found to damage the pump head. In addition, removal of the pump head from the external threads can require a significant force, which can cause damage to the pump head, the inner-tube, or both.
The above-described valve housings are secured to the inner-tube to facilitate the pumping of air through the valve housing and into the inner-tube. This process typically includes attaching a rubber patch to the lower end of the valve housing and then positioning the rubber patch over a hole in the inner-tube. The rubber patch is then secured to the inner-tube (e.g., using adhesive, heat, vulcanization, chemical bonding, or any other appropriate process) to seal the valve housing to the inner-tube. These patches are commonly oval in shape and historically have dimensions of about 30 millimeters long and 17 millimeters wide.
Recently, due to the continuous desire to decrease the weight of bicycles, inner-tubes have been made to have a thinner wall thickness. While many bicycle inner-tubes have historically been made with a wall thickness of 1 millimeter or more, many recent bicycle inner-tubes have a wall thickness of less than 1 millimeter, with some having wall thicknesses of 0.6 millimeters or less. These reduced wall thicknesses have resulted in an increased frequency of flat tires caused by air leaking through holes in the inner-tube. These holes are frequently found in the inner-tube near the valve housing.